Agriculture is responsible for an estimated 14 percent of the world's greenhouse gases. A significant portion of these emissions come from methane, which, in terms of its contribution to global warming, is 23 times more powerful than carbon dioxide. The U.S. Food and Agriculture Organization says that agricultural methane output could increase by 60 percent by 2030 [Source: Times Online]. The world's 1.5 billion cows and billions of other grazing animals emit dozens of polluting gases, including lots of methane. Two-thirds of all ammonia comes from cows.
Cows emit a massive amount of methane through belching, with a lesser amount through flatulence. Statistics vary regarding how much methane the average dairy cow expels. Some experts say 100 liters to 200 liters a day (or about 26 gallons to about 53 gallons), while others say it's up to 500 liters (about 132 gallons) a day. In any case, that's a lot of methane, an amount comparable to the pollution produced by a car in a day.
Read Article